30 Years of Shuttle, 30 Years of the ISS
After three decades of operations, the Space Shuttle has been a “constant background” of U.S. activity in space for several generations. What some outside the NASA world may not know (or remember) is that the Shuttle has been used for significantly different purposes over its 30 years of life. Loosely, its mission history can be characterized in three phases:
- Launch services for commercial and defense purposes (payload deployment and servicing)
- Research in space (civil space payload deployment, and sortie-based experiments)
- Development/testing of space operations and emplacement of space infrastructure (Mir, ISS)
There are not clean breaks between the phases, and of course there is overlap, but they are best illustrated by analysis of the actual primary mission objectives for all Shuttle missions:
(To construct this, I have categorized all primary mission objectives for all missions into more detailed categories below, rolled up into these three top level categories, then smoothed using a “10-consecutive mission” running average.)
Several factors led to this evolution. Loosely, the Challenger accident in 1986 led to the development of alternative (expendable) launch services, both U.S. and by our space partners, leading to the eventual phaseout of Shuttle as payload delivery (or servicing) capability beyond the civil space program. Meanwhile, development of the capabilities and facilities needed for sortie-based (Spacelab, etc) space research took time (and budget) to develop after initial STS capability. Finally, the the International Space Station program stabilized in the early 1990s, attention was focused on prepartory work (Mir) and eventually construction of ISS itself, beginning in 1998. After the Columbia accident, all missions save the Hubble Servicing Mission 4 have been dedicated to ISS assembly.
A little more insight can be gained by breaking the main categories down slightly:
A nice trend that shows up here is how research, and defense/intelligence, spacecraft deployment “lagged” the initial STS capability. (This is due to mission development time scales, as well as available budget). This history is probably worth remembering as NASA embarks on development of a new heavy lift Space Launch System capability.
Lessons for the International Space Station
The broader moral, though, is that the Space Shuttle Program, over its 30-year life, was not “monolithic” in purpose. Ultimately, the underlying capability was deployed towards different purposes as other national and international policies, priorities, capabilities, and resources evolved over the lifetime of the program.
This is worth remembering now that NASA has committed to extending the lifetime of the International Space Station to 2020, and discussions continue around pushing that to 2028. It would by myopic – given the Shuttle history – to assume that the next two decades of ISS’ life will look like its first decade, or that its utilization will continue to be bounded by “traditional” life and microgravity/materials science research. (This despite the very real budget constraints faced today. I’m talking the 30-year view here.) The problem is that the near-term budget woes, near term cost of access, and resource-focused long term mission planning all reinforce a myopic and too-narrowly bounded view of the Space Station’s ultimate potential or fate.
(Note that I am not arguing against the necessity of affordable or sustainable long term mission planning. The problem lies when resource planners enforce and sustain overly linear, bounded, and creativity-limiting perspectives too far into the “out years”, leading to answers which can only be “persistence forecasts” of the portfolio of activities we are doing today. One problem right now is that we have not yet found the right balance between an overly open build from the left capabilities-based perspective, and an overly narrow requirements-driven laser-focused and limiting view of what is needed or possible. Fortunately NASA’s workforce has a long history of cultivating the seeds of “what is possible” in the margins of major programs, and adapting to new national imperatives when they arrive.
I’ll take a mental note to post again here in 2018, and 2028, with similar sand charts for ISS. Whatever they show, I strongly suspect it will be at least partially surprising…
Bonus mashup video for this post… A link to the audio track (from a fantastic album which mixes Central Asian voices, from Bulgarian choirs to Tuvan throat singers) is at the YouTube page:
And, here’s an amazing high-speed video of Shuttle boosters and engines at launch. It’s worth the 45 minutes…